Field of the Invention
The present invention relates to a caulking gun.
Description of the Prior Art
A caulking gun is used to push the gel in the gel tube out. A conventional caulking gun, such as disclosed in patents TW M406469 or U.S. Pat. No. 6,640,998, has a pushing element, a bar-linkage assembly, and a trigger which is connected with the bar-linkage assembly. When the trigger is pressed or pulled, the pushing element is moved due to the motion of the bar-linkage assembly so as to bring a pushing rod move forward. Specifically, the trigger is directly pivotally engaged with one of the bars of the bar-linkage assembly. The motion of the bar-linkage assembly is triggered by the pivoting of the trigger.
However, the angle of pivoting and the position of the trigger are restricted, so the design of movement of the bars is also restricted a lot. Besides, the pressing force of the trigger may be wasted on useless component of force in the complicated bar-system. To move the pushing rod forward, much force is needed.
On the other hand, the complicated bar-system is difficult to manufacture and assemble. The connections between the bars may be stuck due to rusting.